(1) Field of the Invention
The invention relates to a duct arrangement for a filter, which is used in an automobile air conditioning system, for removing smells from the air.
(2) Description of the Related Art
Japanese Unexamined Patent Publication (Kokai) No. 57-172817 describes an automobile air conditioning system which comprises a deodorization filter for removing odors and dust from the air within the passenger compartment. The deodorization filter comprises an energized charcoal for removing odorous substances such as Nox and CH, which are contained in exhaust gas from automobiles and are introduced into the passenger compartment. In addition to the malodor, such substances are bad for the health of passengers within the passenger compartment. The deodorization filter is provided downstream of an evaporator within an air duct. A damper assembly is arranged within the air duct to switch the air between normal mode, in which the air from the evaporator directly distributed into the passenger compartment without passing through the deodorization filter, and deodorization mode, in which the air from the evaporator passes through the deodorization filter for removing the odorous substances. When the deodorization mode is selected, the air, which has passed through the evaporator, is directed to the deodorization filter.
In the air system of JPP '817, the deodorization filter in the air duct hinders the air flow to increase the flow resistance during the normal mode, which results in decrease in the flow rate, increase in noise of the air flow, and increase in power consumption of the fan motor.
Japanese Unexamined Patent Publications (Kokai) No. 4-271916 and No. 5-2718 describe an automobile air conditioning system which comprises main and by-pass air ducts and a deodorization filter, which is provided in the by-pass air duct, for removing odors and dust from the air within the passenger compartment. Provided within the main air duct is a valve or a door for switching the air flow between the main and by-pass air ducts. The deodorization filter is provided within the by-pass air duct to be oriented substantially perpendicular to the direction air flow in the main air duct. Thus, the deodorization filter and the by-pass air duct which encloses the deodorization filter extend outwardly from the main air duct into the passenger compartment of the automobile.
The invention is directed to solve the prior art problems described above, and to provide an air conditioning system improved to minimize the space required for installation as well as the flow resistance during the normal mode.